William p



(Noiaodi.)

W. P. KOOKOGEY.

INCANDESGBNT LAMP.

Nofsilsg. Patented. Nov. 2, 1886.

mn/@6566. Inventor;

YUNITED STATES PATENT OFFICE.-

'WILLIAM r. KOOKOGEY, or BROOKLYN, NEW YORK;

INCANDESCENT LAMP.- 4

SPECIFICATION forming part of Letters Patent'No. 351,869, dated November2, 1886.

l Appnmnon filed June 12, 188s.

'To all whom it may concern:

Beit known that I, WILLIAM P. KOOKOGEY, of Brooklyn, in the county ofKings and State of New York, have invented certainnew and usefulImprovements in Incandescent Lamps, of which the following is aspecication.

My invention relates to filaments or light# giving bodiesfor'incandescent electric lights 5 and the invention 'consists in afilament having a very thin but broad middle portion to v produce alarge radiating-surface with little forms, and,among others, in the formof a dat 'strip widest at its mid-length and narrowing or light-givingsurface.

gradually toward its ends, or in the shape of a slender thread havingits ends thickened to prevent burning away. The more common forms,however, have very small bodies, and consequently offer an exceedinglyhigh resistance, vbesides being difficult to produce and liable to bedestroyed in a short time.

My invention is designed to produce a filament of low resistance but oflarge radiating This I find produces a light more nearly resembling inappearance the ordinary gas-light, which is commonly deemed desirable. v

In the drawings, Figure 1 is a face view of my improved filament; Fig.2, a cross-section of the same on the line a: fr of Fig. l; Fig. 3, atop edge or plan View 0f the filament.Y

A indicates the filament as a whole, composed of a crescent-shaped body,a, and ends or terminals b b. The crescent shape of body a causes thelight to assume a curve or arched form not unlike that of a gas-dame,andthe broad iiat surface givesa large radiating-face, and consequentlylarge amount of light. Be-

ing wider in the middle than elsewhere, the greatest amount of lightwill be at the middle,and will gradually lessen toward the ends orterminals b b. The ends b b are thickened in any convenient manner,according to the material of vwhich the filament is made.

-In practice I prefer to cut or form the filai Serial No. 204,982. (Nomodel.)

ment from bond tissue or other tough and fibrous paper, and when suchmaterial is employed the 'ends b b may be thickened by rolling, folding,or building up of different thicknesses, and after being brought toproper form the Whole is carbonized in the usualway, when it is ready,for use.

The body portion should be made as 4thin as practicable, and the endsshould be made to present as great or greater cross-section (though indifferent form) in order that there may not be undue resistance andconsequent burning out atl the points of attachment-a fault common tomany lamps heretofore made. It is not essential that the lament becurved, nor that, if curved, it be set with the bowed side uppermost.

' The essential feature of the invention consists in making the lamentwider or broader at its middle than at its ends and thickening said endsto prevent undue resistance to the electric current thereby.

I do not claim, broadly, either the widening of the central portion orthe thickening of the end portions of the lament, separately.considered, my purpose being to produce a filament which shall combinethe advantages and avoid the objectionable features of both typesheretofore used, as above mentioned.

Filaments having the broadened middle portion without the thickenedlends offer undue resistance and rapidly burn away at the ends,

and do not givethe greatest intensity of light l in the broad middleportion, where it should be given. Filaments having slender threadlikebodies and thickened ends also offer undue resistance, and do not offerthe extent 'of radiating or illuminating surface that is l. A filamentfor incandeseing eleetrelamps having its middle portion made broaderthan its ends and its ends made thicker than its middle portion,substantially as and for the 3. A earbonized-paper filament forineztndesoing electriolam ps having a thin and broad ro middle portionand narrow thickened ends.

5 purpose set forth. WM' P' KOOKOGEY' 2. The herein-describedincandeseing elec- Witnesses:

WILLIAM XV. DODGE, XVALTER S. DODGE.

trie -light filament, consisting` of crescentshaped body a and thickenedends b b.

